Process for assembling an optical fiber connector

ABSTRACT

A method and apparatus for assembling a multiple component article such as an optical fiber connector and inspecting assembled multiple component articles. The method includes a step of positioning an elongated body with one free end being exposed, positioning a biasing component over the exposed end, positioning a coupling nut over the exposed end and abutting the biasing component, and applying a retaining component to the elongated body to retain the biasing component in a compressed state between the elongated body and the coupling nut. The apparatus includes a fixture or nest for retaining an elongated body of the connector in a selected orientation. Stations of the apparatus are included for placing the elongated body in the fixture in a selected orientation, placing a biasing component on the elongated body, placing a coupling nut on the elongated body over the exposed end and abutting the biasing component, and applying a retaining component to an outside surface of the elongated body for retaining the biasing component between the elongated body and the coupling nut in a compressed state. The inspection system includes a fixture for retaining the multiple component article in a selected orientation in which a portion of the elongated body and a portion of the coupling nut are exposed for inspection. An emitter/detector is provided for identifying the presence of the elongated body and the coupling nut and indicating when the elongated body and coupling nut are properly assembled. Two emitter/detectors are positioned for acting on at least two sites relative to the multiple component article retained in the fixture.

BACKGROUND

The present invention relates to a process and apparatus for assemblinga multiple component article such as a multiple component optical fiberconnector and an inspection system for inspecting such multiplecomponent articles.

Multiple component optical fiber connectors are extremely important tomake critical mechanical connections between the free ends of opticalfibers. More and more systems are using fiber optic technologies toincrease computing power, data transmission volume and speed as well asnumerous other applications. It is important that the connectorssecurely retain the connection between the two pieces of optical fiber.A variety of connectors have been developed to provide such connection.For example, U.S. Pat. No. 5,073,044 to Egner et al., issued Dec. 17,1991, to the Assignee of the present invention, shows an optical fiberconnector having a right angle strain relief.

The general design of the Egner device is typical for optical fiberconnectors. Such a connector includes an elongated body, a coupling nut,biasing means and a retaining ring. The coupling nut and biasing meansare axially arranged on the elongated body and retained in position bythe retaining ring. The biasing means acts against the coupling nut toprovide a secure engagement with the other coupling component with whichit is connected.

Typically, the retaining rings are a C-ring having an open gap along oneside for radial attachment to the elongated body. The C-ring is matedwith an annular groove formed on an outside surface of the elongatedbody. Further, these C-rings are manually attached to the elongated bodyadding delay and cost to the connector assembly process. U.S. Pat. No.5,121,455 to Palecek, issued Jun. 9, 1992, explicitly shows a C-ringused to retain a coupling nut and spring on the elongated body of anoptical fiber connector.

As the demand for fiber optic technology increases so does the demandfor connections between optical fibers. In order to satisfy the demandfor optical fiber connectors, it is preferable to automate the assemblyprocess for assembling optical fiber connectors. As with many otherautomated processes, problems arise with the efficient processing ofnumerous components during the assembly process as well as the mostefficient organization and layout of the process apparatus. It is alsoimportant to automate the inspection process where possible so that theproduction throughput is maintained and bottlenecks, which might becaused by manual inspection, are eliminated.

OBJECTS AND SUMMARY

A general object satisfied by the present invention is to provide amethod of assembling multiple component articles which require preciseplacement of components in an assembly stream and operations on thecomponents during the assembly process.

Another object satisfied by the present invention is to provide anapparatus which automates the assembly of optical fiber connectors in acontinuous process.

Yet another object satisfied by the present invention is to provide aninspection system for multiple component articles which is capable ofdetermining whether each multiple component article is properly orimproperly assembled.

Briefly, and in accordance with the foregoing, the present inventionenvisions a method for assembling a multiple component article such asan optical fiber connector. The method includes the steps of positioningan elongated body with one free end being exposed, positioning a biasingcomponent over the exposed end, positioning a coupling nut over theexposed end and abutting the biasing component, and applying a retainingcomponent to the elongated body to retain the biasing component in acompressed state between the elongated body and the coupling nut.

The present invention also envisions an apparatus for assembling anoptical fiber connector. The apparatus includes a fixture or nest forretaining an elongated body of the connector in a selected orientation.Stations of the apparatus are included for placing the elongated body inthe fixture in a selected orientation, placing a biasing component onthe elongated body, placing a coupling nut on the elongated body overthe exposed end and abutting the biasing component, and applying aretaining component to an outside surface of the elongated body forretaining the biasing component between the elongated body and thecoupling nut in a compressed state.

The invention further envisions an inspection system for inspectingmultiple component articles such as optical fiber connectors. Theinspection system includes a fixture for retaining an optical fiberconnector in a selected orientation in which a portion of the elongatedbody and a portion of the coupling nut are exposed for inspection. Anemitter/detector is provided for identifying the presence of theelongated body and the coupling nut and indicating when the elongatedbody and coupling nut are properly assembled. The emitter detector ispositioned for acting on at least two sites relative to the multiplecomponent article retained in the fixture.

BRIEF DESCRIPTION OF THE DRAWINGS

The organization and manner of the structure and operation of theinvention, together with further objects and advantages thereof, may beunderstood by reference to the following description taken in connectionwith the accompanying drawings, wherein like reference numerals identifylike elements, and in which:

FIG. 1 is a perspective view of a multiple component article in the formof an optical fiber connector as assembled and inspected by the processand apparatus of the present invention;

FIG. 2 is an exploded perspective view of the multiple component articleas shown in FIG. 1 which has been exploded to show the individualcomponents of the optical fiber connector;

FIG. 3 is a cross-sectional side elevational view taken along line 3--3in FIG. 1 of the optical fiber connector in an assembled state;

FIG. 4 is a diagrammatic representation of the process and apparatus ofthe present invention for assembling multiple component articles such asoptical fiber connectors;

FIG. 5 is a cross-sectional side elevational view of the first of aseries of progressive views showing the process of the present inventionin which an elongated body is retained in a fixture of the apparatus ofthe present invention;

FIG. 6 is a cross-sectional side elevational view of the second of theseries of progressive views in which a biasing component is added to theelongated body during the process carried out by the apparatus of thepresent invention;

FIG. 7 is a cross-sectional side elevational view of the third of theseries of progressive views showing the addition of a coupling nut tothe elongated body and biasing component during the process carried outby the apparatus of the present invention;

FIG. 8 is a cross-sectional side elevational view of the fourth of theseries of progressive views showing the application of a retainingcomponent to an outside surface of the elongated body in the processcarried out by the apparatus of the present invention;

FIG. 9 is a reduced scale view showing the arrangement of FIGS. 9A, 9B,9C which are enlarged detailed views of the apparatus of the presentinvention which, even though on separate sheets, actually comprise onefigure;

FIG. 9A shows a station for verifying that a fixture or nest used in theapparatus is free to receive an elongated body and an enlarged plan viewof a station which places an elongated body of the multiple componentarticle on the nest which is indexed through the apparatus;

FIG. 9B shows a station which places a biasing component on theelongated body retained in the fixture and a station which places acoupling nut over the biasing component and the elongated body;

FIG. 9C shows a station which places a retaining component on theelongated body carrying the biasing component and the coupling nut, acontrol device for controlling the apparatus, an inspection station forinspecting the assembled multi-component article, and a device forselectively removing the assembled optical fiber connectors from thenest which operates in response to the results of the inspection;

FIG. 10 is an enlarged partial fragmentary, cross-sectional, sideelevational view taken along line 10--10 in FIG. 9C showing theinspection station in greater detail;

FIG. 11 is an enlarged, partial fragmentary, side elevational view of aproperly assembled optical fiber connector retained in a nest which isinspected by the inspection station shown in FIG. 10 and showing twospaced apart inspection sites imposed thereon;

FIG. 12 is an enlarged, partial fragmentary, side elevational view of animproperly assembled optical fiber connector absent an elongated body;

FIG. 13 is an enlarged, partial fragmentary, side elevational view of animproperly assembled optical fiber connector absent a biasing meanscomponent;

FIG. 14 is an enlarged, partial fragmentary, side elevational view of animproperly assembled optical fiber connector absent a coupling nut;

FIG. 15 is an enlarged, partial fragmentary, side elevational view of animproperly assembled optical fiber connector absent a retainingcomponent attached to the upper outside surface of the elongated body;

FIG. 16 is an enlarged, partial fragmentary, cross-sectional, sideelevational view taken along line 16--16 in FIG. 9C showing a ramportion and a retaining component delivery portion associated therewithfor applying a retaining ring to the optical fiber connector;

FIG. 17 is an enlarged, partial fragmentary, cross-sectional, showingthe retaining component delivery portion for delivering and applying aretaining ring to the outside surface of an elongated body of theoptical fiber connector;

FIG. 18 is a cross-sectional, bottom plan view taken along line 18--18in FIG. 17 showing vacuum channels formed in a vacuum plunger forplacing a retaining ring on an optical fiber connector;

FIG. 19 is an enlarged, cross-sectional view of the tip of the retainingcomponent delivery portion showing a retaining ring retained thereon;

FIG. 20 is a partial fragmentary, top plan view of the retaining ringapply means as shown in FIG. 9C; and

FIG. 21 is a partial fragmentary, cross-sectional view taken along line21--21 in FIG. 20 showing the placement of a retaining ring feedertrack, the delivery of retaining rings to a shuttle block and relativelocation of a retaining ring shim gate.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While the invention may be susceptible to embodiment in different forms,there is shown in the drawings, and herein will be described in detail,an embodiment with the understanding that the present description is tobe considered an exemplification of the principles of the invention andis not intended to limit the invention to that as illustrated anddescribed herein.

With reference to FIG. 1, a multiple component article 20 is shown in aperspective view. In particular, the multiple component article is anoptical fiber connector 20. For purposes of description and explanationof the process and apparatus of the present invention, the optical fiberconnector 20 is used as an example of a multiple component article. Itshould be noted that the present description is not intended to belimited to optical fiber connectors but should include other multiplecomponent articles.

With reference to the exploded perspective view as shown in FIG. 2, theconnector 20 includes a first generally elongated body 22, biasing means24, a second body 26 shown herein as a coupling nut, and retaining means28 shown herein as a continuous retaining ring. A longitudinal axis 30is defined along the direction of elongation of the elongated body 22.Each of the components 22, 24, 26, and 28 are oriented and assembledalong the longitudinal axis 30. Additionally, as it will be described ingreater detail hereinbelow, the connector 20 is assembled with exposedareas which promote inspection of the assembled article using theinspection system of the present invention to determine whether or notthe article is properly assembled.

With further reference to the optical fiber connector 20, the elongatedbody 22 includes a tubular portion 32 which is formed of a plasticmaterial and which is overmolded on a ferrule 34. For purposes of thisdescription, the tubular portion 32 and the ferrule will be referred toas the elongated body 22. The second body or coupling nut 26 is definedby a generally cylindrical wall 36 which, with further reference to FIG.3, has transverse radially, inwardly projecting inner flanges 38 whichdefine a bore 40. The tubular portion 32 extends through the bore 40with the biasing means 24 retained between the flanges 38 and a shoulder42 formed on the tubular portion 32. The coupling nut 26 and the biasingmeans 24 are retained in axial alignment with the tubular portion 32.The biasing means 24 is retained in a compressed state (see FIG. 3)between the inner flanges 38 of the coupling nut 26 and the shoulder 42.Compression of the biasing means 24 maintains a biasing force betweenthe elongated body 22 and the nut 26 to provide a secure mechanicalengagement of the connector 20 with a mating connector (not shown).

With reference to FIG. 3, it should be noted for purposes ofclarification, that a first width dimension 44 is defined betweenoutside surfaces 46 of the elongated body 22. A second width dimension48 is defined between outside surfaces 50 of the coupling nut 26. Thefirst width dimension 44 is generally measured at the shoulder 42 of theelongated body 22. The shoulder end of the elongated body is generallyreferred to as an optical fiber connecting end or the first free end 52of the connector 20 while the opposite end of the elongated body 22 isreferred to as the optical fiber entry end or second free end 54.

An external diameter 56 measured between outside surfaces of the body 58proximate to the second free end 54 is slightly larger than an internaldimension 60 (see FIG. 2) measured between opposed edges 62 of theretaining means 28. As shown in the drawings, the retaining ring hasopposed edges 62, 62 which define an aperture 63 in the retaining ring28. The dimensional difference between the edges 62, 62 of the aperture63 and the outside surface of the elongated body 22 create a frictionfit between the retaining ring 28 and outside surface 58 of theelongated body 22. In fact, when the retaining ring 28 is attached tothe elongated body 22, the inside edges 62 tend to scuff or skive theoutside surface 58 which increases the frictional fit between theretaining ring 28 and the body 22.

Turning now to FIGS. 4-8, a process and apparatus 64 of the presentinvention is described. The apparatus 64 includes a fixture or nest 66which is operatively associated with indexing means 68. The indexingmeans 68 is shown in FIGS. 9A-9C as a table or platform having astationary portion 69 and a rotary dial 71 operatively attached thereto.The indexing means is of known construction to controllably index thenests 66 attached along the perimeter of the rotary dial 71. Theelongated body 22 is positioned in the nest 66 for assembly of theconnector 20. The indexing means 68 advances the nest 66 to a number ofstations comprising the apparatus 64. The stations, describedhereinbelow, are positioned in close proximity to one another in acircular arrangement for minimizing the travel distance, travel motion,and travel time of the nest between stations for increasing through putof the apparatus. The nest 66 retains the elongated body 22 in aselected orientation for assembly of the components 24,26,28 during theassembly process and for inspection after the connector 20 is assembled.Each of the stations is operatively interfaced with the indexing means68 and a controller 67 to deliver a component to the elongated bodypositioned in the nest 66 and/or carry out an action on the connector20.

The nest 66 is first indexed in position to receive an elongated body 22from a body placement station 70. As shown in FIG. 5, the ferrule 34 isinserted into a correspondingly dimensioned-bore 72 formed in the nest66. The bore 72 is axially aligned for coaxially receiving the elongatedbody 22 along the longitudinal axis 30. Once the elongated body 22 isplaced, the indexing means 68 indexes the nest 66 to a biasing meansplacement station or spring placement station 74. The biasing means 24as shown in FIGS. 2, 3 and 5-8 is a coiled spring. As shown in FIG. 6,the coiled spring 24 defines a passage 76 which is coaxially alignedwith the longitudinal axis 30 allowing the spring 24 to be positionedover the exposed free end 54 proximate to the outside surface 58 of theelongated body 22. The spring 24 is limited in its downward axialmovement by the shoulder 42. After the spring 24 is positioned on theelongated body 22, the nest 66 is indexed to a nut placement station 78.As previously described, the coupling nut 26 includes a bore 40 which iscoaxially aligned with the longitudinal axis 30 and positioned over thefree end 54 of the elongated body 22 such that the flanges 38 abut thespring 24. This assembly state is shown in FIG. 7.

Once the coupling nut 26 is placed on the cumulative assembly, the nest66 is indexed to a retaining means mounting station 80. With referenceto FIG. 8, the retaining ring 28 is positioned with the aperture 63coaxially aligned with the longitudinal axis 30. The ring 28 isdownwardly displaced along the longitudinal axis 30. Application of theretaining ring 28 over the exposed free end 54 results in engagementbetween the inner edge 62 of the aperture 63 with the outside surface 58of the elongated body 22. One of the objectives satisfied by the presentinvention is to position the coupling nut 26 and retain it by way of theretaining ring 28 such that the spring 24 is maintained in a compressedstate between the coupling nut 26 and the shoulder 42. To this end, thecoupling nut 26 can be displaced before the application of the retainingring 28 so that the retaining ring 28 is axially driven to theprepositioned location of the coupling nut 26. The retaining ring 28 canalso be driven in a manner such that the coupling nut 26 issimultaneously driven with the retaining ring 28 by forces (as indicatedby reference arrows 82) acting on the retaining ring 28.

As will be described in greater detail hereinbelow, an inspection systemis provided at an assembly inspection station 84 to determine whetherthe connector assembly 20 which is positioned proximate thereto isproperly assembled. The nest unloading station 86 operates in responseto the results of the inspection station 84 to determine whether theassembled article 20 is "good" or "bad", in other words, properly orimproperly assembled, respectively. The nest unloading station 86selectively moves properly connectors 20 to a "good" location 90 andimproperly connectors 20 to a "bad" location 92.

After the nest 66 is unloaded by the nest unloading station 86, the nest66 is then indexed by the indexing means 68 to a nest inspection station94. The nest inspection station 94 is a precautionary measure to assurethat the nest 66 is unloaded so that when the nest 66 is advanced to thebody placement station 70, it is prepared to receive the next elongatedbody 22 for assembly. It should be noted that the indexing means 68 canoperate with a nest 66 at each of the stations so that each station isperforming an operation generally simultaneously.

FIGS. 9A, 9B and 9C are a grouping of drawings which are arranged asshown in FIG. 9, to illustrate the apparatus 64 in greater detail. Forexample, the body placement station 70 as shown in block diagrammaticform in FIG. 4 is illustrated with a vibratory bowl 96 and feeder track98 of known construction. A placement device 100 of known construction,serves a properly oriented elongated body 22 to a correspondinglypositioned nest 66. The bowl 96 and track 98 are of known constructionsuch as is produced by Performance Feeders of Oldsmar, Fla. Numerousbodies 22 are retained in the bowl 96 and feed to the track 98 whichincludes a series of orienting structures to deliver each body in aselected orientation for receipt by the placement device and positioningin the nest 66.

Moving to the drawing sheet identified as FIG. 9B, the nest 66 advancesto the spring placement station 74 which utilizes an air jet feeder 102of known construction connected to a delivery tube 104. A deliverydevice 106 of known construction selectively drops or deposits anaxially oriented spring 24 over the exposed end 54 of the elongated body22. The air jet feeder 102 is of known construction such as the typeproduced by Becher Air Components of New Preston, Conn.

The nut placement station 78 includes a vibratory bowl feeder 108 and acorrespondingly nut orienting track 110 of known construction such asproduced by Performance Feeders of Oldsmar, Fla. A nut delivery device112 of known construction receives a properly oriented coupling nut 26from the track 110 and delivers the nut 26 over the exposed end 54 ofthe elongated body 22.

Progressing now to the drawing sheet identified as FIG. 9C, the nest 66is indexed to the ring placement station 80. The ring placement station80 includes a vibratory or gravity bowl feeder 114 which serves ringsretaining 28 to an orienting track 116. The bowl feeder 114 and track116 are of known construction such as produced by Performance Feeders ofOldsmar, Fla. The track 116 serves retaining rings 28 to a ringescapement assembly 118 which will be described in greater detailhereinbelow. The ring escapement assembly 118 delivers and applies aretaining ring over the exposed free end 54 of the elongated body 22.The ring escapement assembly 118 also drives the retaining rings 28axially along the longitudinal axis 30 and simultaneously displaces thecoupling nut 26 to a desired position along the longitudinal axis 30thereby compressing the spring 24 between the shoulder 42 and theflanges 38.

Next, the nest 66 is advanced to the inspection station 84. Theinspection station 84 is shown with greater detail in the partialfragmentary, cross-sectional side elevational view as shown in FIG. 10.The inspection station 84 includes a beam inspector assembly 119 havingemitter means 120 and detector means 122. The emitter 120 is positionedon one side of the connector 20 travelling in the nest 66 and thedetector 122 is positioned on the opposite side of the nest 66 facingthe emitter 120. The beam inspector assembly 119 is generally of knownconstruction such as is produced by Omron Corp. U.S.A. of Schaumburg,Ill. The assembly 119 includes a transmitter/receiver unit 124 which hasa light source for transmitting light over a optical fiber cable 125 tothe emitter/detector pair.

A first beam 126 is produced between a lower emitter and detector pair120,122 and a second beam 127 is produced between an upper emitter anddetector pair. The detector is similarly connected via an optical fibercable 129 to carry the light sensed from the emitter to thetransmitter/receiver unit 124. As shown in FIG. 10, a pair of beaminspector assemblies 119 are used to sense two separate sites relativeto the connector 20.

An output signal from the assemblies 119 is communicated to the nestunloading station which selectively moves the properly or improperlyassembled connectors to a corresponding "good" location 90 or a "bad"location 92. The nest is once again indexed to the nest inspectionstation 94 to verify whether the nest 66 has been emptied.

To further clarify the inspection system of the present invention,reference is made to FIGS. 10-15. The inspection system inspects for theproper or improper assembly of the connector 20. The inspection systemoperates using only two beams 126, 127 to test for at least five statesof the connector 20 shown herein as the optical fiber connector. Withreference to FIG. 10, the emitters 120 are positioned so that the firstbeam 126 will follow a path through a first detecting area 130 (see FIG.11) and the second detector will produce the second beam 127 falling ina second detecting area 132 (see FIG. 15). As shown in FIG. 11, thefirst detecting area 130 is defined between a plane 134 generallyparallel to the axis 30 and passing tangential to an outside surface 135of the nut body 26 and a plane 136 passing along the outside surface 137of the elongated body 22, a plane 138 bounded by an upper surface 139 ofthe nest 66, and a plane 140 defined by an opposing rim edge 142 of thenut 26. In a properly assembled connector 20, the first beam 126 willpass through the first detecting area 130 and fall upon thecorresponding detector 122. The first detecting area 130, therefore,passes along an exposed portion 144 of the elongated body 22 and doesnot block by the coupling nut 26 or the nest 66.

With reference to FIG. 15, the second detecting site 132 is definedbetween the plane 134 along the outside surface 135 of the coupling nut26, the plane 136 along the outside surface 137 of the elongated body22, the plane 140 defined by the rim edge 142 of the coupling nut 26 anda plane 141 bounded generally by the upper surface of the shoulder 42.It is important that the beam path 127 be positioned near the edge ofthe plane 141 towards the nest 66 to detect the position of the couplingnut 26 in a properly assembled connector 20 (see FIG. 11).

We now turn to FIGS. 12-15 to show the alternate conditions of animproperly assembled article and how such an improperly assembledarticle is detected by the two beam inspection assemblies 119. In FIG.12, the connector 20 is assembled without an elongated body 22. As such,the rim edge 142 of the coupling nut 26 rests against the upper surface139 of the nest 66. In this condition, the first beam 126 passingthrough the first detecting site 130 is broken and not sensed by thecorresponding detector. This condition indicates that the connector 20is improperly assembled.

A similar condition is sensed in the improperly assembled connector 20as shown in FIG. 13. In FIG. 13, the connector 20 has been assembledwithout a spring 24 and therefore the rim edge 142 of the nut is allowedto travel downwardly along the elongated body 22 and rest upon the uppersurface 139 of the nest 66. Since the first beam 126 passing through thefirst detecting site 130 is broken, the inspection means 84 senses animproperly assembled connector 20.

FIGS. 13 and 15 show improperly assembled connectors 20 which result inthe second beam 127 passing through the second detecting site 132. Withreference to the discussion hereinabove, the inspection means 84identifies a connector 20 as being properly assembled if the first beam126 is allowed to pass through the first detecting site 130 and thesecond beam 127 is broken in the second detecting site 132. With this inmind, the connector 20 as shown in FIG. 14 is a improperly assembledwithout a nut 26 and as such, the second beam 127 is allowed to passthrough the second detecting site 132 thereby indicating an improperlyassembled connector 20. Similarly, the connector 20 as shown in FIG. 15has been improperly assembled without a retaining ring 28 and thereforthe spring 24 is not retained in compression between the nut 26 and theshoulder 42. In this condition, the nut 26 is displaced upwardly alongthe body 22 and therefore does not block the second beam 127 passingthrough the second detecting site 132. Since the second beam 127 passesthrough the second detecting site 132, the inspecting means 84identifies this as improperly assembled connector.

With reference to FIGS. 9C and 16-21, the retaining means mountingstation 80 is shown and includes the feeder 114 and track 116 whichdeliver retaining rings to a ring locating means 150 for attachment to aconnector retained in a nest by ring applying means 152. In the interestof clarity, the feeder 114 and track 116 are only fully shown in FIG. 9Cwith fragmentary portions of the track illustrated in FIGS. 20 and 21.The ring locating means 150, shown in plan view in FIG. 9C and in theenlarged plan view of FIG. 20, operates to horizontally position a ringrelative to a corresponding nest. Ring applying means 152, shown in aplan view in FIG. 9C and partial fragmentary, side-elevational views inFIGS. 16, 17 and 19 operates to capture a ring from the locating means150 and vertically position and apply the ring on the connector retainedin the nest. The ring applying means 152 includes driving means 154shown herein as a vertically oriented ram of known construction.

Two vertically aligned, spaced-apart support structures 158 are attachedto the stationary portion 69 of the indexing means 68. A cross member160 extends between the vertical support members 158. A clearance space162 is defined between a lower edge 164 of the cross member 160 and atop surface 166 of the dial 71. The dial 71 rotates through the space162 to position a nest and a connector 20 positioned thereon relative tothe ring applying means 152 for applying a retaining ring to theconnector 20.

With reference to FIG. 9C, retaining rings are fed from the vibratorybowl 114 through the track 116 which arranges the retaining rings in adesired orientation through techniques and structures known in the art.As shown in FIG. 20, a gate assembly 168 is positioned between an end170 of the track 116 and the locating means 150. The gate assembly 168includes a shim gate 170 which reciprocates along a guide 171 in frontof the track 116 by means of a dual acting cylinder 172. The gateassembly 168 controllably restricts the movement of retaining rings fromthe vibratory track 116 to the locating means 150. The locating means150 includes a shuttle body 174 having a recess 176 formed therein whichis sized and dimensioned for receiving a retaining ring.

With reference to FIG. 21, the track 116 is vibrated to promote theadvancement of the retaining rings towards the shuttle 174. When thegate 170 is retracted by the dual acting cylinder 172, the first ring inthe que in the track 116 will advance into the recess 176 for horizontalpositioning relative to and for subsequent capture by the applying means152. The cylinder 172 then cycles to return the gate to a positionbetween the first ring, now located in the recess 176, and the secondring in the que so as to retain the rings in the que.

Having fed a ring to the shuttle 174, it can be seen in FIG. 20 that theshuttle 174 of the locating means 150 is operable to horizontallyposition (as indicated by arrow 177) the retaining ring relative to thenest 66. The shuttle 174 is moved (177) by a dual acting cylinder 180,this movement (177) is axially constrained by a guide bearing 178. Theguide bearing 178 restricts the movement of the shuttle 174 along acentral axis 182 so that precise repeatable locating can be achieved bythe operation of the cylinder 180 for dependable placement of theretaining rings relative to the applying means 152.

As shown in FIG. 21, an annular vacuum orifice 184 communicating withthe recess 176 allows a vacuum line 186 to draw a vacuum on the recess176 and thereby retain the ring on the shuttle 174. (The vacuum line 186is not shown in FIG. 20 in the interest of clarity.) This vacuum orifice184 prevents the ring positioned on the shuttle 174 from becomingdisplaced in the recess 176. The shuttle 174 is advanced to a positionunderneath the applying means 152 whereupon a ring applying head 188produces forces which lift the ring from the shuttle and retain the ringon the head 188 for vertical placement onto a connector 20. Withreference to FIGS. 16, 17 and 19 the head 188 retains a ring forplacement over the free end 54 of a connector 20 retained in a nest 66therebelow. The drive means 154 vertically downwardly displaces the head188 during the applying process (see FIG. 19).

A preferred embodiment of the applying head 188 creates a vacuum forceto lift the ring off of the shuttle 174 which is precisely positionedimmediately below the head 188. Further details with regard to thevacuum operated embodiment as shown herein will be provided hereinbelow.In an alternate embodiment, a magnetic head may be used to capture thering from the shuttle and retain the ring for vertical displacement ontoa connector. As shown in FIGS. 17 and 19, in either embodiment, the ringis retained on the head 188 and applied by the applying means 152 ontothe connector 20. The head 188 is axially advanced along a central axis190 generally coaxial with the axis 30 of the connector 20. The ring isdownwardly displaced over the free end 54 of the elongated body 22.

As shown in FIG. 19, the aperture 63 of the retaining ring 28 ispositioned over the free end 54 of the elongated body. The retainingring 28 is moved downwardly along the outside surface 58 of theelongated body 22. As the head 188 is downwardly advanced (as indicatedby arrows 82) toward the coupling nut 26, the ring 28 abuts the innerflanges 38. Further driving of the head along the central axis 190drives (as indicated by arrows 191) the coupler nut 26 downwardlythereby compressing the spring 24. The head is retracted after applyingthe retaining ring 28 to the body 22, with the frictional forces betweenthe inner rim of the aperture 63 and the outside surface 58 of the body22 dislodging the ring from the head 188.

As disclosed hereinabove, the preferred embodiment of the head 188employs vacuum forces to pick up the ring from the shuttle. The vacuumoperated head 188 is shown in greater detail in FIG. 17-19. Withreference to FIG. 17, the vacuum head 188 includes a sleeve 192 which isretained by a set screw 194 on a head body 196. The sleeve 192 has ahollow cavity 198 which communicates with a vacuum line 200. An axiallydisplaceable vacuum plunger 202 is positioned in the cavity 198 withinthe sleeve. The vacuum plunger 202 includes a trailing portion 204, aleading portion 206 and a tapered portion 208 positioned between theleading and trailing portions 206,204. Channels 210 are formed throughthe tapered portion 208 and the leading portion 206 generally parallelto the central axis 190. The channels 210 communicate with an annulargap 212 formed between the tapered portion 208 and an inside surface 214of the sleeve 192. The channels 210 run towards the leading portion 206and communicate with a recess 216 formed in a face 218 of the leadingportion 206. A protruding tip 220 extends from the recess and projectsinto a correspondingly positioned aperture 222 formed in the protrudingend 224 of the sleeve 192.

The aperture 222 and the tip 220 are sized and dimensioned such that agap 226 is formed between the outside surface of the tip 220 and theinside surface of the aperture 222. This gap 226 communicates with therecess 216 and channels 210 to induce a vacuum therethrough. An annularcounterbore 228 is formed in the protruding end 224 of the sleeve 192.When the vacuum is activated, a ring positioned thereunder on theshuttle 174 is lifted from the shuttle onto the sleeve 192. Whenpositioned against the protruding end 224, an extending portion 230 ofthe ring is received in the counterbore 228 with the tip 220 positionedfor protruding through the aperture 63 in the ring. The portion of thering surrounding the aperture 63 is drawn against the sleeve under theinfluence of the vacuum.

A vacuum sensor 232 on the vacuum line 200 senses whether or not thevacuum has changed. Since the vacuum force is a generally consistentforce, the force will change as a result of a ring being positionedagainst the sleeve 92. If the vacuum sensor 232 does not sense a changein the vacuum force, a condition indicating that a ring has not beenpicked up will be produced. When the sensor 232 senses that a ring hasnot been picked up, the apparatus can position the head 188 to make asecond attempt to pick up a ring or can provide an indication to theoperator that this failure condition exists. In either event, the sensor232 provides feedback as to the success of each ring pick up operation.

In use, the retaining means mounting station 80 positions rings relativeto the connector positioned on a nest as each nest is indexed relativeto the ring applying means 152. A plurality of rings are fed from thefeeder to the track 116 under vibratory action whereupon they aresequentially positioned on a shuttle 174 of the ring locating means 150.The gate assembly 168 is employed to meter individual rings from thetrack 116 to the recess 176 in the shuttle 174. The gate assembly 168constrains a que of rings and controllably releases a single ring intoan empty recess 176.

The shuttle 174 is reciprocated (177) relative to the applying means 152to precisely and repeatably position a ring beneath the ring applyinghead 188. In the preferred embodiment as illustrated herein, the shuttleincludes a vacuum which is activated when a ring is positioned in therecess 176. The vacuum is drawn through the annular orifice 184 toretain the ring in the recess 176 on the shuttle 174. Once the shuttlepositions the ring underneath the applying head, the vacuum drawnthrough the annular orifice 184 and the vacuum drawn through theapplying head 188 are synchronously deactivated and activated,respectively. Deactivating the shuttle vacuum allows the activatedapplying head vacuum to precisely lift the ring off of the shuttle andonto the end 224 of the sleeve 192. The shuttle 174 is retracted and anest is advanced into position underneath the applying head 188.

The applying head is driven downwardly (82) to position the ring overthe free end 54 of the elongated body 22. When the head is drivendownwardly, the aperture 222 passes over and along the outside of theelongated body 22. During the displacement of the head 188 along theaxis 190, a spring 234 retained in a bore 236 of the plunger 202 iscompressed by the axial displacement of the plunger 202 within thecavity 198. When the ring is properly positioned along the elongatedbody 22, the head is retracted upwardly along the axis 190 therebyremoving the elongated body 22 from the aperture 222. The upwarddisplacement of the head results in the plunger 202 moving downwardlythrough the cavity 198 under the influence of the compressed spring 234.The spring forces position the plunger 202 such that the tip 220 onceagain is positioned within the aperture 222. The tip 220 is positionedagainst the free end 54 of the elongated body 22 until the body 22clears the aperture 222 to prevent the body 22 from being caught in thesleeve and lifted from the nest. The completed connector retained in thenest is advanced out of position relative to the retaining meansmounting station 80 and is advanced to the assembly inspection station84 for operations as discussed hereinabove.

The nest 66 is indexed into position for inspection at the inspectionstation 84 in accordance with the description provided hereinabove.After inspection, the nest and the assembled connector are advanced tothe nest unloading station in accordance with the description providedhereinabove. Finally, the nest is indexed to the nest inspection station94 as shown in FIG. 9. The nest inspection station operates inessentially the same manner as the assembly inspection station 84 exceptthat only one beam is produced across the nest. The beam is positionedto pass above the nest in alignment with the bore 72. If the nest isempty, the beam path is connected and an empty nest signal istransmitted to the controller. If a component such as the elongated body22, biasing means 24, coupling nut 26, or retaining ring 28 arepositioned on the nest, the beam path is disrupted by the componentthereby indicating that the nest is not empty. A loaded nest signal istransmitted to the controller which alerts an operator by means of avisual or auditory signal. The operator can then remove the componentfrom the loaded nest on the fly or, preferably, stopping the processusing any one of several stop buttons 238 positioned around the indexingtable. The loaded nest is then cleared and the operator reinitiates theassembly process by operating appropriate controls on the controller.

While a preferred embodiment of the present invention is shown anddescribed, it is envisioned that those skilled in the art may devisevarious modifications of the present invention without departing fromthe spirit and scope of the appended claims. The invention is notintended to be limited by the foregoing disclosure.

The invention claimed is:
 1. A method of assembling an optical fiberconnector including an elongated body having a longitudinal axis andopposed free ends, a coupling nut operatively associated with saidelongated body, biasing means positioned between said elongated body andsaid coupling nut, and retaining means being attachable to saidelongated body abutting said coupling nut for retaining said biasingmeans in compression between said coupling nut and said elongated body,said method comprising the steps of:positioning said elongated body withone free end being exposed; positioning said biasing means over saidexposed free end of said elongated body for placing said biasing meanson said elongated body; positioning said coupling nut over said exposedfree end of said elongated body for placing said coupling nut on saidelongated body, said coupling nut abutting said biasing means; movingsaid coupling nut relative to said elongated body for compressing saidbiasing means between said coupling nut and said elongated body; andgenerally simultaneously with the step of moving said coupling nut,applying said retaining means for engaging an outside surface of saidelongated body to retain said biasing means in a compressed state.
 2. Amethod of assembling an optical fiber connector as recited in claim 1,wherein said retaining means is a continuous ring having an inner rimdefining an aperture, further comprising the steps of:axially aligningsaid aperture of said continuous ring with said elongated body; andaxially displacing said continuous ring relative to an outside surfaceof said elongated body.
 3. A method of assembling an optical fiberconnector including an elongated body having a longitudinal axis andopposed free ends, a coupling nut operatively associated with saidelongated body, biasing means positioned between said elongated body andsaid coupling nut, and retaining means being attachable to saidelongated body abutting said coupling nut for retaining said biasingmeans in compression between said coupling nut and said elongated body,said method comprising the steps of:positioning said elongated body withone free end being exposed; positioning said biasing means over saidexposed free end of said elongated body for placing said biasing meanson said elongated body; positioning said coupling nut over said exposedfree end of said elongated body for placing said coupling nut on saidelongated body, said coupling nut abutting said biasing means;positioning said retaining means over said exposed free end of saidelongated body; contacting a portion of said retaining means with acorresponding outside surface of said elongated body; driving saidretaining means along said elongated body to a selected location forplacing said biasing means in compression between said coupling nut andsaid elongated body; and engaging said retaining means with an outsidesurface of said elongated body for retaining said biasing means incompression.
 4. A method of assembling an optical fiber connector asrecited in claim 3, further including the step of inspecting saidoptical fiber connector as assembled to determine whether said opticalfiber connector is properly assembled.
 5. A method of assembling anoptical fiber connector as recited in claim 4, further including thestep of selectively moving said optical fiber connector to a goodconnector location or an improperly assembled connector location inresponse to the results of the inspection step.
 6. A method ofassembling an optical fiber connector as recited in claim 3, furthercomprising the steps of indexing a fixture retaining said elongated bodysequentially through the assembly steps.